The error message you are seeing indicates that there may be an issue with the installation of MATLAB.
Here are some steps you can try to resolve the issue:
- Restart MATLAB and try to open Add-Ons again. Sometimes this can resolve the issue.
- Check if there are any updates available for MATLAB. If there are, install the updates and try to open Add-Ons again.
- Repair the MATLAB installation. To do this, go to the Control Panel on your computer, select "Programs and Features", and find MATLAB in the list of installed programs. Right-click on MATLAB and select "Repair".
- If the issue persists, try uninstalling and reinstalling MATLAB. Make sure to back up any important files or settings before doing so.